Identifying a rectangular area in a multi-projector system

Abstract

Determining a rectangular area with a given aspect ratio within a global boundary formed by multiple projectors. An iterated process is repeated at moved locations along the global boundary, until a stopping condition is met. According to the iterated process, a point at a location of the global boundary is selected, a minimum rectangle with the given aspect ratio is grown from identified directions, and the largest rectangle encountered is delivered when the stopping condition has been met. For each such direction, the minimum rectangle is grown in the direction from the selected point until it intersects with a boundary, the grown rectangle is grown in another direction responsive to a determination that the grown rectangle can grow in another direction. The largest rectangle encountered previously is replaced, responsive to a comparison which indicates that the grown rectangle is larger than the largest rectangle encountered previously.

What is claimed is: 
     
       1. A method for determining a rectangular area with a given aspect ratio within a global boundary formed on a projection surface by multiple projectors, the method comprising:
 repeatedly performing an iterated process at moved locations along the global boundary until a stopping condition has been met, 
 wherein the iterated process comprises: 
 selecting a point at a location of the global boundary, 
 identifying directions aligned with a minimum rectangle positioned at the selected point in which the minimum rectangle with the given aspect ratio can be grown from the selected point, 
 wherein for each such direction: 
 growing the minimum rectangle with the given aspect ratio in the direction from the selected point until it intersects with a boundary of the global boundary, 
 determining whether the grown rectangle can grow in another direction responsive to the grown rectangle intersecting with the boundary of the global boundary, 
 growing the grown rectangle in the other direction responsive to a determination that the grown rectangle can grow in the other direction, 
 comparing the grown rectangle with a largest rectangular area encountered previously, and 
 replacing the largest rectangle encountered previously responsive to a comparison which indicates that the grown rectangle is larger than the largest rectangle encountered previously, 
 wherein the method further comprises: 
 delivering the largest rectangle encountered responsive to a determination that the stopping condition has been met. 
 
     
     
       2. The method of  claim 1 , wherein the global boundary comprises a polygonal boundary formed by distorted projections of rectangles by all of the multiple projectors in a projector array onto the projection surface. 
     
     
       3. The method of  claim 2 , wherein the global boundary comprises a concave polygon. 
     
     
       4. The method of  claim 1 , wherein the moved location along the global boundary is a location moved by a predetermined interval. 
     
     
       5. The method of  claim 1 , wherein the minimum rectangle grows by a predetermined interval. 
     
     
       6. The method of  claim 1 , wherein the stopping condition comprises a determination that the entirety of the global boundary has been traversed. 
     
     
       7. A module for determining a rectangular area with a given aspect ratio within a global boundary formed on a projection surface by multiple projectors, the module comprising:
 a growing module constructed to repeatedly perform an iterated process at moved locations along the global boundary until a stopping condition has been met, 
 wherein the iterated process comprises: 
 selecting a point at a location of the global boundary, 
 identifying directions aligned with a minimum rectangle positioned at the selected point in which the minimum rectangle with the given aspect ratio can be grown from the selected point, 
 wherein for each such direction: 
 growing the minimum rectangle with the given aspect ratio in the direction from the selected point until it intersects with a boundary of the global boundary, 
 determining whether the grown rectangle can grow in another direction responsive to the grown rectangle intersecting with the boundary of the global boundary, 
 growing the grown rectangle in the other direction responsive to a determination that the grown rectangle can grow in the other direction, 
 comparing the grown rectangle with a largest rectangular area encountered previously, and 
 replacing the largest rectangle encountered previously responsive to a comparison which indicates that the grown rectangle is larger than the largest rectangle encountered previously, 
 wherein the module further comprises: 
 a delivering module constructed to deliver the largest rectangle encountered responsive to a determination that the stopping condition has been met. 
 
     
     
       8. The module of  claim 7 , wherein the global boundary comprises a polygonal boundary formed by distorted projections of rectangles by all of the multiple projectors in a projector array onto the projection surface. 
     
     
       9. The module of  claim 8 , wherein the global boundary comprises a concave polygon. 
     
     
       10. The module of  claim 7 , wherein the moved location along the global boundary is a location moved by a predetermined interval. 
     
     
       11. The module of  claim 7 , wherein the minimum rectangle grows by a predetermined interval. 
     
     
       12. The module of  claim 7 , wherein the stopping condition comprises a determination that the entirety of the global boundary has been traversed. 
     
     
       13. An apparatus for determining a rectangular area with a given aspect ratio within a global boundary formed on a projection surface by multiple projectors, the apparatus comprising:
 a computer-readable memory constructed to store computer-executable process steps; and 
 a processor constructed to execute the computer-executable process steps stored in the memory; 
 wherein the process steps stored in the memory comprise computer-executable process steps to: 
 repeatedly perform an iterated process at moved locations along the global boundary until a stopping condition has been met, 
 wherein the iterated process comprises: 
 selecting a point at a location of the global boundary, 
 identifying directions aligned with a minimum rectangle positioned at the selected point in which the minimum rectangle with the given aspect ratio can be grown from the selected point, 
 wherein for each such direction: 
 growing the minimum rectangle with the given aspect ratio in the direction from the selected point until it intersects with a boundary of the global boundary, 
 determining whether the grown rectangle can grow in another direction responsive to the grown rectangle intersecting with the boundary of the global boundary, 
 growing the grown rectangle in the other direction responsive to a determination that the grown rectangle can grow in the other direction, 
 comparing the grown rectangle with a largest rectangular area encountered previously, and 
 replacing the largest rectangle encountered previously responsive to a comparison which indicates that the grown rectangle is larger than the largest rectangle encountered previously, 
 wherein the process steps further comprise: 
 delivering the largest rectangle encountered responsive to a determination that the stopping condition has been met. 
 
     
     
       14. The apparatus of  claim 13 , wherein the global boundary comprises a polygonal boundary formed by distorted projections of rectangles by all of the multiple projectors in a projector array onto the projection surface. 
     
     
       15. The apparatus of  claim 14 , wherein the global boundary comprises a concave polygon. 
     
     
       16. The apparatus of  claim 14 , wherein the moved location along the global boundary is a location moved by a predetermined interval. 
     
     
       17. The apparatus of  claim 14 , wherein the minimum rectangle grows by a predetermined interval. 
     
     
       18. The apparatus of  claim 14 , wherein the stopping condition comprises a determination that the entirety of the global boundary has been traversed. 
     
     
       19. A computer-readable storage medium on which is retrievably stored computer-executable process steps for determining a rectangular area with a given aspect ratio within a global boundary formed on a projection surface by multiple projectors, the process steps comprising:
 repeatedly performing an iterated process at moved locations along the global boundary until a stopping condition has been met, 
 wherein the iterated process comprises: 
 selecting a point at a location of the global boundary, 
 identifying directions aligned with a minimum rectangle positioned at the selected point in which the minimum rectangle with the given aspect ratio can be grown from the selected point, 
 wherein for each such direction: 
 growing the minimum rectangle with the given aspect ratio in the direction from the selected point until it intersects with a boundary of the global boundary, 
 determining whether the grown rectangle can grow in another direction responsive to the grown rectangle intersecting with the boundary of the global boundary, 
 growing the grown rectangle in the other direction responsive to a determination that the grown rectangle can grow in the other direction, 
 comparing the grown rectangle with a largest rectangular area encountered previously, and 
 replacing the largest rectangle encountered previously responsive to a comparison which indicates that the grown rectangle is larger than the largest rectangle encountered previously, 
 wherein the process steps further comprise: 
 delivering the largest rectangle encountered responsive to a determination that the stopping condition has been met. 
 
     
     
       20. The computer-readable storage medium of  claim 19 , wherein the global boundary comprises a polygonal boundary formed by distorted projections of rectangles by all of the multiple projectors in a projector array onto the projection surface. 
     
     
       21. The computer-readable storage medium of  claim 20 , wherein the global boundary comprises a concave polygon. 
     
     
       22. The computer-readable storage medium of  claim 19 , wherein the moved location along the global boundary is a location moved by a predetermined interval. 
     
     
       23. The computer-readable storage medium of  claim 19 , wherein the minimum rectangle grows by a predetermined interval. 
     
     
       24. The computer-readable storage medium of  claim 19 , wherein the stopping condition comprises a determination that the entirety of the global boundary has been traversed.